I've been digging into this. The entire K5/K6 fiche lists four guides, 36619-41G00, 58621-41G00, 58621-29G00, and 58622-41G00 (other guides are listed, but they're for things like the cam chain). I see four around the steering head so that must be them. The first is in the wiring section and the other three are in the handlebar section. Three of the four are only used on K5/K6 1000. I've been able to find pics of two:
Both are on my K6, the first attaches high on the left frame rail about even with the front tank mounting screws. The second attaches low on the right rail and has the clutch cable plus the ignition & right handlebar wiring bundles.
My bike also has a guide for the left handlebar wiring bundle so it must be the 36619-41G00 part. It attaches low on the left rail. It's similar to 58621-41G00 except that the opening is smaller.
Here're the right side drawings from 10-21 of the service manual with the leaders removed:
It looks like my guide and it must be 58622-41G00. The drawing in the fiche is completely wrong (the draftsman must have been hung over as there are errors in the drawings of all four guides). I'm fairly sure that mine is OEM as you have to unbolt the ignition switch to remove the guide. I unbolted it several years ago and remember that the orange-red threadlock was present and made removal difficult.
I can find guides that are vaguely similar to 58622-41G00. You can see one here from a K1-K3 600:
I was hoping to find a drawing that was close enough to use to update the parts manual that I produced. So far no luck.